2000 Legacy L Wagon, just put a newer EJ25 in it. The shop that did the work failed to check the oil pan and put in a VERY dented pan. They also filled it with 5qts of oil. I drained out a good qt of oil, and the level is now sitting on the max level notch on the dipstick. This solved my struggle to idle until lunch today. Now its dropping to roughly 200 rpm after I accelerate, and picks itself back up. no problems accelerating, runs great at all points other than mentioned.

 

I'm concerned the oil pump was damaged by the shops idiotic 5qt fill with an obviously damaged oil pan. The engine knock she sensor is faulty as well, comes on sometimes and stays on until I leave the car off for about ten minutes or until I clear it.

Edited October 4, 201312 yr by Unit562

This may or may not help.

IAC.htm

This may or may not help.

That's a lot of money for only a chance of working. I'm replacing the oil pan, going to inspect the pickup. Hopefully its not that.

 

Now that I actually drive it a good distance, it feels like that's the problem.

Edited October 5, 201312 yr by Unit562

The dented oil pan will not cause it to idle rough. It may starve the bearings of oil because it often blocks the pickup tube screen which prevents the oil pump from sucking oil out of the pan. This quickly leads to knocking and other interesting clattering noises as the rod bearings chew themselves to bits. No noise, no harm, but still a good idea to replace the pan. (Make the shop do it)

 

These engines have a hard time dropping under 400 rpm without stalling. They just don't have the rotational mass to keep them spinning below that.

If you don't have a CEL with a code for a misfire, I would suspect the IAC needs to be cleaned, and check any vacuum hoses for loose fit and cracks.

The dented oil pan will not cause it to idle rough. It may starve the bearings of oil because it often blocks the pickup tube screen which prevents the oil pump from sucking oil out of the pan. This quickly leads to knocking and other interesting clattering noises as the rod bearings chew themselves to bits. No noise, no harm, but still a good idea to replace the pan. (Make the shop do it)

 

These engines have a hard time dropping under 400 rpm without stalling. They just don't have the rotational mass to keep them spinning below that.

If you don't have a CEL with a code for a misfire, I would suspect the IAC needs to be cleaned, and check any vacuum hoses for loose fit and cracks.

Fortunately the pan is not dented on the bottom, only on the sides. I'll pull the IAC apart tonight and check it out.